Two-way solenoid-operated control valves are electro-mechanical valves designed for use with fluid flows whereby the valve is controlled between open and closed conditions by energizing and de-energizing a solenoid coil. Solenoid valves are used in numerous applications where control of fluid flow and distribution is desired. For example, solenoid valves are useful for gas management systems, where the flow of a gaseous or liquid medium can be controlled to operate, in part, a generator system without undesired waste of energy or resources.
Solenoid valves typically comprise an armature assembly including a plunger and a seal for seating engagement with a valve seat. In accordance with standard operation of such valve-types, the valve can be operated between closed and open conditions upon energization of a solenoid. Such valves can be normally closed valves, where the valve is closed until the solenoid is energized to open the valve and allow a fluid flow through the valve. Alternatively, such valves can be normally open valves, where the valve is open until the solenoid is energized to close the valve and shut off the fluid flowing through the valve.
More particularly, in a normally closed valve design, when the solenoid is energized, the plunger will move to engage and unseat the seal from the valve seat to open the valve and allow a fluid to flow through the valve. When the solenoid is de-energized, the plunger and seal return to the seated position to close the valve and block the fluid from flowing through the valve until the solenoid is energized again. Alternatively, in a normally open design, the valve is in an open condition when there is no power applied to the solenoid, and the plunger moves to engage the seal and seat to close the valve when the solenoid is energized. Typically in a two-way normally open valve, the valve seat is located at the top of the sleeve and the seal is located at the top of the plunger.
Solenoid valves having a basic plunger and seal design have not been desirable for high pressure, high flow applications, typically due to low reliability and the high forces involved under such conditions. Additionally, in two-way normally open applications, the valve seat location at the top of the sleeve limits the seat size, which restricts the maximum allowable flow of fluid through the valve. An exemplary solenoid valve design that may operate at relatively high pressure is described in U.S. Pat. No. 4,027,850, incorporated herein by reference. There, a solenoid valve includes an integral seal pin guide surface that surrounds an associated projecting portion of the seal pin to guide it into seating engagement with the valve seat in order to maintain the seal pin in precise alignment therewith under all pressure conditions.
High pressure, high flow applications also present particular issues for normally open valve designs. As noted, a normally open solenoid valve keeps the valve open when the solenoid is de-energized, and thus permits fluid to flow through the valve until the solenoid is energized to close the valve. Depending on the media flow direction through the valve seat, with high pressure and high flow, the plunger must either overcome the high pressure and high flow in order to close the valve, or very heavy return spring loads must be deployed to open the valve when de-energizing. Accordingly, the solenoid must supply sufficient electro-magnetic force on the plunger to either adequately counteract the fluid flow in order to close the valve, or overcome the heavy return springs employed. Conventional, normally open valve designs are susceptible to leakage and/or premature failure and thus have not been reliable in high-pressure conditions.
Other solenoid valve designs utilize a two-stage plunger or poppet follower-style valve design. Such designs provide control over fluid flow through the valve. However, two-stage plunger valves have also shown low reliability in high pressure, high flow applications. The two-stage plunger valves typically do not handle high pressure, high flow, in two-way normally open valve designs.
Accordingly, there is a need for a solenoid-operated control valve that can handle high pressure, high flow applications, utilizing a two-way, normally open valve design. There is also a need for a solenoid valve design that can handle high pressure, high flow applications without unnecessarily increasing the size or complexity of the valve or the system in which the valve is incorporated. There is further a need for a solenoid valve design that provides desired operation capabilities without being difficult to operate, manufacture, or incorporated into larger systems.